The Republican presidential candidate doesn't talk much about his role in the Mormon Church, but he served as a bishop in a Boston-area church and presided over 12 congregations as stake president.

Reporting from Belmont, Mass. — In a closely-knit Mormon congregation, Ronnie Catalano was a problem Mitt Romney wanted to solve.

As bishop — a position akin to priest or pastor — Romney presided over a fast-growing flock that included Catalano's wife, Sandy, a new convert. Ronnie, a cigarette smoking, wine-drinking Catholic, had accused Sandy of ruining their family by becoming Mormon. He tried to prevent her from attending church and from donating their money in the Mormon tradition of tithing.

Sandy was thinking of leaving her husband and moving to Utah with their two children, an anathema in a faith in which families come first and church leaders are encouraged to bring non-Mormon spouses of church members into the fold.

What followed, the Catalanos say, was an extended campaign of kindness and faith that went far beyond what Romney was obligated to do as bishop. Romney took the Catalanos under his wing. He called Ronnie to invite him to church events, gave him tasks such as manning a grill or setting up tables to make him feel included, invented jobs around the church when Ronnie was out of work. He referred Ronnie to passages in the Book of Mormon that spoke to the importance of families, and told the Catalanos that he was praying for them, and even losing sleep over them.

In 1991, after 11 years of persuasion, Ronnie Catalano converted to Mormonism. The 67-year-old Budweiser driver is now deeply involved in the church and has given up smoking and drinking, which he says saved his life because his father and brother both died of lung cancer.

"Mitt was the one who really stood out. He was always caring about my family, my wife, my children," Catalano said in a recent interview. "He taught me how to keep my family together."

"He saved us. He rescued us," added his wife.

George W. Bush is a born-again Christian; President Obama has been a regular church-goer for decades; Jimmy Carter taught Sunday school. But no previous president or serious candidate can rival Romney for the time and energy spent in running a religious organization and ministering to its members.

Over the course of two decades, Romney served as spiritual and administrative leader for a Boston-area church and then as the head of a dozen Mormon churches. The work often took up 30 hours a week of his time, or more.

Had he not entered politics, Romney — a sixth-generation member of the Mormon Church whose ancestors were among the earliest members of the faith — might have put himself on a path to be chosen for the church's governing body in Salt Lake City, the Quorum of the Twelve Apostles.

Faith-based credentials such as Romney's are normally gold on the campaign trail. Yet Romney does not speak of his time as a church leader in Belmont. His Republican presidential campaign biography doesn't mention any of his church roles, not even his stint as Sunday school teacher.

"People in his campaign wished he'd never been a Mormon or a Mormon leader," said Ronald B. Scott, a fellow Mormon and the author of a just-published book about Romney, "Mitt Romney: An Inside Look at the Man and His Politics." "They haven't said, 'How do we turn this sow's ear into a silk purse?' And he doesn't talk about it."

Romney knows well the political perils of a Mormon background. According to a Gallup poll, nearly 20% of Republican and independent voters say they wouldn't support a Mormon for president. Others might agree with the Rev. Robert Jeffress, an evangelical Texas preacher who caused a stir in October when he called Mormonism a cult just before introducing Texas Gov. Rick Perry at the Values Voters Summit in Washington.

Romney's service to the church "is something that most Americans would admire," said David Campbell, associate professor of political science at the University of Notre Dame, who is Mormon. "But if he begins to talk about his service, then it would open up all the other questions about his religion."

Romney was the bishop of the Belmont ward from 1981 to 1985, the "shepherd of the flock," said Kim Clark, president of Brigham Young University-Idaho and a member of the congregation at the time. Romney was not paid for his service in Belmont or Boston; in the Mormon Church, congregation members are responsible for running all pieces of church life as volunteers.

His responsibilities included visiting the sick, meeting with youth groups, counseling married couples and delinquent children, arranging Sunday services, church classes and other events, and using Scriptures and the Book of Mormon to guide his congregation.